The present invention relates to tool guiding and marking devices and more particularly to guides and markers which are clamped to a workpiece. As such, the invention will be hereinafter called a "guide clamp".
Guide clamps are not new and the patent to William J. Fortune, U.S. Pat. No. 3,287,808 is exemplary of the prior art. The basic features of a guide clamp include a guide bar having a pair of gripping jaws at one side of the bar to clamp onto a workpiece such as a board. One jaw, the clamping jaw, is at one end of the bar. The other jaw, the shifting jaw, may be positioned along the reach of the bar to bring the jaws against the edges of the workpiece and the clamping jaw will then secure the guide clamp onto the workpiece. The guide clamp may be used for various purposes such as for marking or as an abutment for a power hand saw which is held against the guide clamp as it makes a cut across the workpiece.
The present invention, an improved guide clamp, was conceived and developed to make possible a heretofore unrealized potential for such a tool, especially for precision and custom woodworking. A conventional guide clamp can serve as a guiding abutment for a power hand saw but the guide clamp is not always satisfactory for other types of power hand tools such as a router. The vibration and other action of such a tool can move the tool away from the edge of the guide clamp even when it is tightly held. An improved guide clamp which will positively hold and guide a tool across a workpiece is needed. Also, a guide clamp which can be precisely positioned on a workpiece to hold jigs and the like for precision operations is needed.